Towards On-Chip Bayesian Neuromorphic Learning
This addresses the need for uncertainty signaling in edge devices for critical applications like healthcare or military, though it is incremental as it builds on existing neuromorphic learning methods.
The paper tackles the problem of enabling edge devices to signal uncertainty in critical applications by proposing a Bayesian neuromorphic learning algorithm that can be computed with only local information, demonstrating its effectiveness on a store-recall problem to learn good uncertainty over time.
If edge devices are to be deployed to critical applications where their decisions could have serious financial, political, or public-health consequences, they will need a way to signal when they are not sure how to react to their environment. For instance, a lost delivery drone could make its way back to a distribution center or contact the client if it is confused about how exactly to make its delivery, rather than taking the action which is "most likely" correct. This issue is compounded for health care or military applications. However, the brain-realistic temporal credit assignment problem neuromorphic computing algorithms have to solve is difficult. The double role weights play in backpropagation-based-learning, dictating how the network reacts to both input and feedback, needs to be decoupled. e-prop 1 is a promising learning algorithm that tackles this with Broadcast Alignment (a technique where network weights are replaced with random weights during feedback) and accumulated local information. We investigate under what conditions the Bayesian loss term can be expressed in a similar fashion, proposing an algorithm that can be computed with only local information as well and which is thus no more difficult to implement on hardware. This algorithm is exhibited on a store-recall problem, which suggests that it can learn good uncertainty on decisions to be made over time.